Prepare the Cake:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan or line it with parchment paper.
2. Mix Dry Ingredients: In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, nutmeg, and salt. Set aside.
3. Cream Butter and Sugar: In a large mixing bowl, beat the softened butter and brown sugar together until light and fluffy, about 3-4 minutes.
4. Add Eggs and Vanilla: Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the vanilla extract.
5. Add Dry Ingredients and Milk: Gradually add the dry ingredients to the butter mixture, alternating with the milk, beginning and ending with the dry ingredients. Mix until just combined.
6. Fold in the Apples: Gently fold in the chopped apples, ensuring they’re evenly distributed throughout the batter.
7. Bake the Cake: Pour the batter into the prepared cake pan and spread it out evenly. Bake for 45-50 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Prepare the Toffee Sauce:

8. Make the Toffee Sauce: In a saucepan over medium heat, melt the butter. Stir in the brown sugar and cook until the sugar dissolves and the mixture starts to bubble.
9. Add Cream and Vanilla: Slowly pour in the heavy cream, stirring constantly. Let the sauce simmer for 2-3 minutes until thickened. Remove from heat and stir in the vanilla extract.

Assemble the Cake:

10. Pour the Toffee Sauce: Once the cake has cooled, place it on a serving plate. Pour half of the toffee sauce over the top of the cake, allowing it to soak in.
11. Serve: Serve the cake warm or at room temperature with the remaining toffee sauce on the side for drizzling.